Racheal Mathews works on a copper flame-painted butterfly in the studio she shares with her husband, Skip, at the Ozark Folk Center in Mountain View.

MOUNTAIN VIEW — Some people paint with acrylics. Others paint with watercolors. Skip and Racheal Mathews paint with fire.

The Mathewses are copper colorists, using heat to “paint” on copper by controlling the metal’s oxidation.

Skip is known as the Father of Flame Painting, having developed the technique 35 years ago. He taught his wife how to paint with the flame 14 years ago, and in the last six years, the couple have been teaching their craft to others.

“We’ve come up with a vocabulary for teaching it,” Racheal said. “I was the second person Skip had taught, so he had not developed a vocabulary of how to explain what he had been doing for years. It was a series of mistakes, and some of the mistakes would work, so it was just trial and error.”

The Mathewses teach flame painting at the Arkansas Craft School in Mountain View, and John Van Orman, husband of the school’s executive director, Terri Van Orman, said the Mathewses’ classes are always full and well received.

“They’re delightful people to work with,” he said. “We like our students to be happy, of course, and we can always rely on Skip and Racheal to bring in good feedback.”

There are 14 main colors that come out of the copper when it is heated to different temperatures, and Skip and Racheal use those colors to create patterns on pieces of copper shaped as butterflies, dragons, pendants, crosses and fish, among other options.

There are 23 to 33 steps to create each copper piece, including cleaning, heating, cooling, reheating and finishing the pieces with a coat of polymer.

“I used to question that when I was first apprenticing with Skip,” Racheal said. “And then I sat down and counted them and found out that was right.”

Skip and Racheal use propane and oxygen in a small torch to bring out the color through the oxidation that forms on the surface naturally when the copper is introduced to heat. They bring the piece of copper to its warmest oxidation level — signified with a gray surface — and then allow it to cool a bit before applying the torch again and bringing out the cooler colors.

“I will use the side of the flame,” Racheal said of bringing out the cooler colors. “It’s a reduction atmosphere, so it will take the oxidation off in little shapes that I design. So it’s my drawing tool.”

There are three main factors that play into the color of the copper: how hot the metal is, how many time it is heated and what other elements may be in the air at the time. Getting color is one thing, but being able to paint with it is another.

“Anybody can get color on copper,” Racheal said. “But we’re flame painters because we’ve learned how to control the color and make it go where we want it to. Even with that, we figure we have about 70 to 80 percent control. If you’re a control freak, this is not the medium for you.”

Racheal said flame painting has helped her enjoy the process instead of being too concerned about a “perfect” outcome. In her first year as a flame painter, she said, she had a lot of “happy accidents” that helped her learn more about the process.

“I always say my husband is a ‘bubble off center,’ so he does all of the abstract stuff,” she said. “I am the ‘Queen of Symmetry.’ We’re a great complement to each other.”

The Mathewses are originally from Arizona, where they both studied art at the University of Arizona. When they got married in 1996, they moved to Branson, Mo., to continue making art. In 2012, after they traveled “one too many times” to Mountain View to teach at the Arkansas Craft Center, they made the decision to make their home in Arkansas and have a shop at the Ozark Folk Center, Racheal said.

“The Ozark Folk Center is an art community and a craft village. They understand what the artists have to do in order to make a living,” Racheal said. “That is very unusual.”

The Mathewses have a class scheduled at the Arkansas Craft School for May 19 through May 21. The class is currently full, but the school is accepting names for a waiting list.